1. Field of the Invention
This invention is directed to rotatable fluid conductors for conducting pressurized fluid to well apparatuses and particularly to a top drive with such a conductor.
2. Related Applications and Description of Prior Art
A variety of problems are associated with the use of prior art rotatable fluid conductors. In many prior art devices it is difficult to properly effect a metalto-metal contacting rotary seal and often, once this is achieved, the contact of metal-to-metal causes galling or excessive wear.
In accordance with .sctn.1.56 of 37 C.F.R., the following are disclosed:
______________________________________ U.S. Pat. No. ______________________________________ 4,529,045 Top drive with sealing rotatable fluid conductor 3,695,669 Rotatable fluid conductor for elevator 4,449,596 Top drive for wells 4,625,977 Rotary seal assembly 4,256,313 Universal mechanical seal gland ______________________________________ Publication Varco Top Drive Drilling System Description and Specifications Technical Bulletin, May 1985, (see pp. 22-24) TorqueRight Top Drive Drilling System, 1986
Prior art top drives are discussed in our copending U.S. patent application entitled "Hydraulic Top Drive for Wells", Ser. No. 07/016,980 filed Feb. 26, 1987 and in the prior art cited therein. Prior art elevator link tilt mechanisms are discussed in our copending U.S. patent application Ser. No. 07/099,771 filed Sept. 22, 1987 and our assembly includes a rotatable sealing gland.
There has long been a need for an efficient and effective rotatable fluid conductor or seal. There has long been a need for an efficient and effective rotatable fluid conductor which permits non-contacting movement of a drive shaft or of a portion of the conductor on the shaft until the fluid conductor is energized. There has long been a need for an efficient and effective drilling and well apparatuses including, but not limited to, a top drive apparatus which such a non-contacting rotatable fluid conductor. The present invention recognizes, addresses, and satisfies these long-felt needs.